412 research outputs found
MOVING TOWARD OPEN GEOSPATIAL SYSTEMS: THE UN OPEN GIS INITIATIVE
Abstract. The UN Open GIS Initiative is an ongoing Partnership Initiative leaded by the United Nations Geospatial Operations. The Initiative, established in March 2016, is supported by several UN Member States, UN Field Missions, UN Agencies and technology contributing partners (international organizations, academia, NGOs, and the private sector) and takes full advantage of their expertise.The target is the creation of an extended spatial data infrastructure that meets the requirements of the UN Secretariat (including UN field missions and regional commissions), and then expands to UN agencies, UN operating partners and developing countries. The paper presents the activities done in the past year and the status of the Initiative
Motivating and Sustaining Participation in VGI
Volunteers are the key component in the collection of Volunteered Geographic Information (VGI), so what motivates their participation, what strategies work in recruitment and how sustainability of participation can be achieved are key questions that need to be answered to inform VGI system design and implementation. This chapter reviews studies that have examined these questions and presents the main motivational factors that drive volunteer participation, as determined from empirical research. Some best practices from broader citizen science applications are also presented that may have relevance for VGI initiatives. Finally, a set of case studies from our experiences are used to illustrate how volunteers have been motivated to collect VGI through mapping parties, gamification and working with schools
BIG GEO DATA MANAGEMENT: AN EXPLORATION WITH SOCIAL MEDIA AND TELECOMMUNICATIONS OPEN DATA
The term Big Data has been recently used to define big, highly varied, complex data sets, which are created and updated at a high speed and require faster processing, namely, a reduced time to filter and analyse relevant data. These data is also increasingly becoming Open Data (data that can be freely distributed) made public by the government, agencies, private enterprises and among others. There are at least two issues that can obstruct the availability and use of Open Big Datasets: Firstly, the gathering and geoprocessing of these datasets are very computationally intensive; hence, it is necessary to integrate high-performance solutions, preferably internet based, to achieve the goals. Secondly, the problems of heterogeneity and inconsistency in geospatial data are well known and affect the data integration process, but is particularly problematic for Big Geo Data. Therefore, Big Geo Data integration will be one of the most challenging issues to solve. With these applications, we demonstrate that is possible to provide processed Big Geo Data to common users, using open geospatial standards and technologies. NoSQL databases like MongoDB and frameworks like RASDAMAN could offer different functionalities that facilitate working with larger volumes and more heterogeneous geospatial data sources
The ESQUIRE project: Quantum Dots as scintillation detectors
The primary goal of ESQUIRE (Experiment with Scintillating
Quantum dots for Ionizing Radiation Events) is the development of a new family of scintillation detectors based on scintillating nanocrystals coupled to high-quantumefficiency solid-state detectors. These detectors will be designed for the search of neutrinoless double-beta decay (0νββ), therefore an excellent energy resolution in
the region of interest for the study of 0νββ (∼2% around 3 MeV) is mandatory. One of the main advantages in this approach is the easy mass scalability, which makes ESQUIRE a competitive option for next-generation experiments. During the discussion the project goal will be presented, alongside the first optical characterization of QD samples
Increased luminescence efficiency by synergistic exploitation of lipo/hydrophilic co-solvency and supramolecular design
We use steady-state and time-resolved photoluminescence (PL) spectroscopy to investigate the luminescent properties of a sulfonated poly(diphenylenevinylene) lithium salt (PDV.Li) in water/propanol solutions at different concentrations, with a view to assessing its aggregation behavior. In particular, we compare results from uninsulated PDV.Li and cyclodextrin-threaded PDV.Li polyrotaxane (PDV.Li⊂β-CD). We find that addition of 1-propanol (≥20 weight%) leads to a significant blue-shift (of ∼0.20 eV) of the PL spectra, that we assign to suppressed interchain aggregation in PDV.Li solutions, with a concomitant fourfold increase in the fluorescence quantum efficiency (i.e. from 14 to 60%). Surprisingly, a moderate concentration of propanol increases further the luminescence efficiency even for PDV.Li⊂β-CD, whose supramolecular encapsulation already provides a shield against aggregation. Indeed, addition of propanol reduces the solvent polarity, and therefore helps solubilizing these materials that are still largely aromatic in nature. Interestingly, however, both uninsulated PDV.Li and polyrotaxane solutions exhibit signs of aggregation at high propanol fraction (>70%) with a distinctively weaker coupling than that of interchain states in PDV.Li at high water concentration and in pure water in particular. While we ascribe such behavior to a poor solvation of the polar moieties, we also report a different strength of aggregation for PDV.Li and PDV.Li⊂β-CD that can be attributed to the presence of the cyclodextrin rings. In PDV.Li⊂β-CD hydrogen bonding between the cyclodextrin rings may lead to closer packing between the polymer chains. We therefore suggest that a content of propanol between 30 and 70% provides a good balance of hydrophobic and hydrophilic interactions both for PDV.Li and PDV.Li⊂β-CD
Synthesis of highly luminescent wurtzite CdSe/CdS giant-shell nanocrystals using a fast continuous injection route
We synthesized CdSe/CdS giant-shell nanocrystals, with a CdSe core diameter between 2.8 nm and 5.5 nm, and a CdS shell thickness of up to 7–8 nm (equivalent to about 20 monolayers of CdS). Both the core and shell have a wurtzite crystal structure, yielding epitaxial growth of the shell and nearly defect-free crystals. As a result, the photoluminescence (PL) quantum efficiency (QE) is as high as 90%. Quantitative PL measurements at various excitation wavelengths allow us to separate the nonradiative decay into contributions from interface and surface trapping, giving us pathways for future optimization of the structure. In addition, the NCs do not blink, and the giant shell and concurring strong electron delocalization efficiently suppress Auger recombination, yielding a biexciton lifetime of about 15 ns. The corresponding biexciton PL QE equals 11% in 5.5/18.1 nm CdSe/CdS. Variable-temperature time-resolved PL and PL under magnetic fields further reveal that the emission at cryogenic temperature originates from a negative trion-state, in agreement with other CdSe/CdS giant-shell systems reported in the literature
Innovation in GI teaching and learning: a case-based approach
giCASES – Creating a University-Enterprise Alliance for a Spatially Enabled Society – is a Knowledge Alliance co-funded within the EC ERASMUS+ Programme. General objectives: a) To enable and strengthen innovation in GI education and industry; b) To facilitate the collaborative creation, management and sharing of knowledge. These objectives are addressed by developing new, innovative and multidisciplinary approaches to teaching and learning within the Geographic Information (GI) sector, and facilitating the exchange, flow and co-creation of knowledge. In particular, giCASES aims to: a) Improve the quality and relevance of GI courses provided by the University members of the consortium; b) Facilitate the growth of new knowledge-sharing processes and tools between enterprises and universities; c) Improve the management of knowledge by the partners. The overall approach to address these objectives is to develop new learning material and processes based on case-based learning. In the approach taken in the project, enterprises and academia collaborate both when creating learning material based on real cases and also during and after the courses (through a collaborative platform)
Innovation in GI teaching and learning: a case-based approach
There is a need to align the geospatial education and training offered by European universities with the requirement of the private and public sector to have access to a well-trained Geographic Information workforce. Over the past decades the collaboration between academia and the private and public sector gained importance in research as well as education. However, a more intense collaboration and more innovative methods are necessary to cope with the challenges of the fast evolving technological developments in the geospatial and ICT fields. In the context of the giCASES Erasmus+ project, a case-based and collaborative learning method has been designed based on the concept of co-creation of knowledge. Six case studies have been identified and described to test the approach. The case studies have been analysed and modelled with focus on three collaborative learning patterns. This poster describes the approach, the identified case studies, as well as the collaborative learning patterns. In ongoing and future work, the different patterns will serve as use cases for the deployment of a collaborative learning platform and for testing the co-creation of knowledge
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